Why Care About Performance?

Shopzilla improved Website performance by 3.5 seconds and conversion rate went up 7-12% and page views went up 25%

Bing and Google added added 200ms to a page it took people 500ms to make a first click. People get out of their flow when performance degrades

Over time, as you slow down user experience, people’s interactions get worse and worse. Even when people’s performance gets improved, if you lost them before, they may not come back. Build performance into your process.

Active users are the ones most impacted by performance. Time to click is two times worse than the delay was. Your users care about performance.

The biggest thing you can do to improve performance is reduce file size and number of http requests. CSS is a factor in both of these. We have to do CSS right.

CSS Issues

CSS code is too fragile -even the cleanest code can get ruined by the first non-expert to work on it. CSS requires expert ability to just get started.

Code re-use is almost non-existent. Most people start over when writing CSS.

Because of these issues, file size just keeps getting.

CSS Cascade

Browsers all have default styles. All these internal style sheets are different. A CSS reset sheet can make things equal across browsers.